"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

At least they've added sequestration to the list. There has been little consensus within the IPCC on this in the past. Opposition ironically cited un-quantifiable unknowns. I always wondered if this was a model programming issue or was there just a lack of interest.

"That number isn’t just growing, its growth is accelerating. Over the previous decade, it increased by about one billion tons each year, while the average from 1970-2000 was about 0.4 tons more each year. "

Was that 1970-Y2K average supposed to be more like 0.4 GIGAtons/yr? Otherwise "accelerating" hardly does it justice.

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

How does C correspond to purchasing power? If you spend $2 on a loaf of bread rather than $1, does that double your contribution to GDP, or does it remain the same?

"That number isn’t just growing, its growth is accelerating. Over the previous decade, it increased by about one billion tons each year, while the average from 1970-2000 was about 0.4 tons more each year. "

Was that 1970-Y2K average supposed to be more like 0.4 GIGAtons/yr? Otherwise "accelerating" hardly does it justice.

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

How does C correspond to purchasing power? If you spend $2 on a loaf of bread rather than $1, does that double your contribution to GDP, or does it remain the same?

It depends upon where you got that extra dollar from. Did you not buy something else? Did you take it out of an account that was otherwise used for investment? Did it come from a tax break on your regular or investment income which would otherwise have been part of government spending?

What the report seems to be saying is that C will be slightly depressed over the years due to shifts in spending in other areas. For example, investment in more expensive energy will increase investment and government spending (increasing GDP) but impact manufacturing and consumer goods negatively (probably due to higher energy costs during transition).

The transition to renewables, however, will provide other benefits such as reduced long-term energy costs, defense spending due to energy stability, etc.

All of these (plus many other factors) have gone into the GDP estimates in the report.

At least they've added sequestration to the list. There has been little consensus within the IPCC on this in the past. Opposition ironically cited un-quantifiable unknowns. I always wondered if this was a model programming issue or was there just a lack of interest.

Those oxymoronic "un-quantifiable unknowns" are still there. Largely. But there has been considerable progress on the capture front. Google "igcc css" and "ccgt css" for examples. I pulled up two earlier today: Combined Cycle Plant for Power Generation and Integrated-Gasification Combined Cycle Advanced Gas Turbine Combustion. So that end begins to look promising. The sequestration part -- well the U.S. produces about 1 billion tons coal each year. Most of that is thermal coal, emitting about 3.7 Gigatons CO2 yearly. That's a *lot* of CO2 to sock away for a rainy day. But the magnitude of the CO2 problem illustrates the magnitude of replacing our existing coal plant. That's a lot of baseload to replace, hence the interest in CCS.

China has it even worse: they consume 3.8 Gigatons/yr for 14 Gigatons CO2 each year , and 60 percent of that is by efficient modern (and pricey) plant built since Y2K. They aren't going to give that up overnight (or stop building them, sigh), and these plants live a nominal 50 years. CCS does not look as far-fetched as it does dire necessity.

I have the sinking feeling that our selfish and greedy civilization will ignore these recommendations, nothing will really change, and we'll be staring in the face of a 5 degrees Celsius increase. All the while the denialists will keep on claiming that it's all a big liberal hoax, and there's nothing to worry about.

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100. (Global consumption accounts for most of GDP.) Consumption has been increasing by 1.6 to 3 percent each year, so that reduction still allows for a great degree of growth.

would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100. (Global consumption accounts for most of GDP.) Consumption has been increasing by 1.6 to 3 percent each year, so that reduction still allows for a great degree of growth.

I still don't see how a reduction allows an increase.

The annual reduction due to climate change mitigation is something like 0.06 percent in a number that is increasing, due to other factors, by 1.6 - 3 percent per year. So, a small decrease due to mitigation isn't enough to wipe out the much higher increases from normal growth.

would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100. (Global consumption accounts for most of GDP.) Consumption has been increasing by 1.6 to 3 percent each year, so that reduction still allows for a great degree of growth.

I still don't see how a reduction allows an increase.

The annual reduction due to climate change mitigation is something like 0.06 percent in a number that is increasing, due to other factors, by 1.6 - 3 percent per year. So, a small decrease due to mitigation isn't enough to wipe out the much higher increases from normal growth.

Sorry, still not getting it. Yes, the 0.06 was in the article. Is it supposed to be a decrease in the rate of increase? I don't see how it says anything like that. I see 5% total decrease in consumption vs 3% annual increase in consumption. Can't increase it at all every year if in 86 years it needs to be 5% less.

would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100. (Global consumption accounts for most of GDP.) Consumption has been increasing by 1.6 to 3 percent each year, so that reduction still allows for a great degree of growth.

I still don't see how a reduction allows an increase.

The annual reduction due to climate change mitigation is something like 0.06 percent in a number that is increasing, due to other factors, by 1.6 - 3 percent per year. So, a small decrease due to mitigation isn't enough to wipe out the much higher increases from normal growth.

Sorry, still not getting it. Yes, the 0.06 was in the article. Is it supposed to be a decrease in the rate of increase? I don't see how it says anything like that. I see 5% total decrease in consumption vs 3% annual increase in consumption. Can't increase it at all every year if in 86 years it needs to be 5% less.

They aren't saying GDP (or consumption) needs to be 5% less than it is today. They are saying that consumption will grow at a rate that will be 5% lower by that date. The rate of increase will be 5% lower, not the total figure at that date.

In other words, this is a decrease in rate of growth, not a decrease in the absolute value. Consumption will be 5% lower than it otherwise would have been without mitigation, but actual consumption will continue to grow each year much faster than mitigation will be slowing it.

In the short term, the report says that the replacement of coal plants with natural gas is a positive step

Really? It seems like a massive waste of money to me? It'd take 10 years to get them off the ground and then they'd need to be shut down by around 2050 right?

Surely billions/trillions of dollars spent worldwide on natural gas plants would be better spent on something renewable or nuclear?

Nuclear is not politically feasible in the wake of what happened in Fukishima. It would be more feasible to build more natural gas plants to replace coal. With the right political will, we could get it done in less than 10 years. Environmentalists often stop these kinds of projects, but they are well aware of the dangers of climate change and the need to reduce emissions. They're ready to deal to get traction on that going.

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

How does C correspond to purchasing power? If you spend $2 on a loaf of bread rather than $1, does that double your contribution to GDP, or does it remain the same?

It depends upon where you got that extra dollar from. Did you not buy something else? Did you take it out of an account that was otherwise used for investment? Did it come from a tax break on your regular or investment income which would otherwise have been part of government spending?

Suppose you didn't buy something else. In other words, you previously were able to buy two loaves of bread for $2, and now you only buy one for $2. Does this count as a decrease in GDP or does it remain constant?

No problem. According to the environmentalists all we need to do is build lots more windmills and solar panels. Never mind the pesky math that shows how unrealistic that is.

Yup the environmentalists are just like the denialists or any idealogical "ists" for that matter. This crisis calls that we go beyond simple ideologies and individual scientific solutions by adopting a truly integrated approach as the IPCC alludes. There are a myriad of reasons why renewable energy solutions have been cost prohibitive - from controlling oil interests to government influence and lack of research. However, the economic viability of renewable energy is rapidly improving.

Even with the economics in our favor, we're now at a point where its imperative that we pull our collective heads out of our ideologies and economic habits.

Of course when things get bad enough, we could just build a transparent aluminum shell around our planet to protect us like our atmosphere does. Oh on second thought - i don't think we should mess with our amazing semipermeable membrane of an atmosphere that keeps us so delicately and tenuously alive in the extraordinarily harsh vacuum of space.

I'll give them a good place to start. Back off of the plastic packaging. We don't need every product packaged in plastic. Less plastic equals less waste that doesn't get recycled, less oil used to make it, less energy used to refine it, and less aggravation trying to open some of that packaging.

As IPCC chairman Ranjendra Pachauri emphasized, “What comes out very clearly from this report is the fact that the high-speed mitigation train would need to leave the station soon, and all of global society would have to get onboard.”

Not going to happen. Neither the lay public nor policy makers are any good at taking steps now that will benefit society 10 years later, never mind acting to avoid a future that may happen 40 years from now.

If that were not true, Social Security wouldn't be a perpetual political football.

This came up at work the other day; my immediate neighbors include a conservative-leaning moderate libertarian (small 'l'), a left-leaning moderate libertarian (still small 'l'), a neocon, and myself, a radical centrist. So obviously my goal is to get them all yelling at each other, but as the debate progressed and they finally looked at me and said "Hey, you're going to be on the liberal side of this argument, what do you have to say?" I just responded "Doesn't matter whether you believe in climate change or not. We're going to be extinct in 200 years if we can't figure out space colonization no matter who wins the argument."

Which of course stopped the original argument and began a series of incredulous questions. It ranged from "CO2 concentrations in ice have to go somewhere" to "sure, we can survive a sea height change, but there will be less arable land available and fresh water will be even more scarce. So humanity may survive but you probably won't, even if you're a prepper." Which then led us down the prepper path. I couched it all as analytic training for them and so, in a rare stroke of compromise, everyone was happy at the end of a climate change discussion.

As the world moves away from significant investors and toward changes in habits, the need for significant investments becomes less.

Already, American consumers are using less oil and gas.

If America were to regain its global leadership, we'd cut our consumption even more and spend our time building more efficient homes, buying renewables.

since the economy of the planet is in the hands of consumers, this is where education and information are crucial. its another reason we need to be vigilant about the rampant, sociopathic restrictions happening on the Internet - the network of networks. The FCC 2.0 should really provide the guidance for an honest, fair and human centric network of networks protocol base.

The 'network' owners like ATT/Verizon/Comcast would need to comply to connect their craptasitc 'network' to our Internet. That is how we assure access to the latest science, data, and decision making tools by consumers - the engine of the global economy.

"While there’s a lot of uncertainty in estimates of the economic cost of this mitigation, the report says hitting the two degrees Celsius target would probably mean lower consumption—something like two percent in 2030, three percent in 2050, and five percent in 2100."

I'm curious how they reach these numbers. In order for this to be true, wouldn't renewables have to cost at most 5% more than fossil fuels? Is that a reasonable assumption?

They are talking about economic consumption. The "C" in C+G+I+NX in calculating GDP.

How does C correspond to purchasing power? If you spend $2 on a loaf of bread rather than $1, does that double your contribution to GDP, or does it remain the same?

It depends upon where you got that extra dollar from. Did you not buy something else? Did you take it out of an account that was otherwise used for investment? Did it come from a tax break on your regular or investment income which would otherwise have been part of government spending?

Suppose you didn't buy something else. In other words, you previously were able to buy two loaves of bread for $2, and now you only buy one for $2. Does this count as a decrease in GDP or does it remain constant?

Ok, you're really stretching the limits of my memory of macro from college. I think in the case you now are asking about GDP would remain unchanged at the most simplistic level of your model. Of course we should still think about other aspects such as what happened to the loaf of bread you didn't buy.

I think what you are asking is what the impact of inflation is on GDP. If we just look at the CPI, that doesn't include either food or energy because of their volatility. As I recall, some inflation is inevitable with a constantly rising GDP, but I don't remember much about the reverse, other than inflation over a certain amount is really bad since it increases unemployment, but at low levels is relatively benign.

I'd suggest looking at a macro textbook for a detailed answer about inflation affecting GDP, particularly in the food and energy sectors which would be special cases.

Keep in mind, though, that consumption is just one part of the GDP equation. To make it even more complex, with a rising GDP, we need a rising money supply as well, which also impacts inflation.

Short of a change of heart with regards to the adoption of modern nuclear power, I think you'll find that the only realistic way to meet the ascribed targets is an aggressive reduction in world population.

In the short term, the report says that the replacement of coal plants with natural gas is a positive step

Really? It seems like a massive waste of money to me? It'd take 10 years to get them off the ground and then they'd need to be shut down by around 2050 right?

Surely billions/trillions of dollars spent worldwide on natural gas plants would be better spent on something renewable or nuclear?

They don't *have* to be shut down by 2050, and they're being built in place of much worse coal plants.

Also i would hope that by 2050 we'd have enough battery technology breakthroughs to enable nearly every car sold to be electric.

According to the article, two thirds of power needs to be zero emission by 2050. I think it's safe to assume we will only achieve that if the one third of emission for power generation is combustion engines for moving cargo/people around. And 100% of power needs to be zero emission by 2100, so the gas plants would need to be shut down by then.

Maybe I'm wrong, other people smarter than me should me making decisions like this. But from my viewpoint it seems like we should be spending money on zero emission technology.

The state I live in apparently has some of the biggest natural gas reserves in the world, and there is a huge PR campaign to adjust legislation to allow those reserves to be mined. I personally hope it fails, I'd like to see the money spent on renewables or nuclear instead.

It would benefit me a lot to have my state export natural gas all over the world, the boost to our local economy would be huge. But I still don't want it to happen.

Short of a change of heart with regards to the adoption of modern nuclear power, I think you'll find that the only realistic way to meet the ascribed targets is an aggressive reduction in world population.

Environmentalists often stop these kinds of projects, but they are well aware of the dangers of climate change and the need to reduce emissions. They're ready to deal to get traction on that going.

Evidence?

On their record, environmentalists block and oppose most any sort of development; i.e., their actions are objectively indistinguishable from luddites.

Which is what their movement is all about, truth be told.

Please don't generalise like that. Not all environmentalists oppose every development, some of us only oppose the worst ones.

In my case I usually don't oppose anything, but sometimes I do want changes made before a development plan goes ahead. For example I would be perfectly fine with coal power plants if all (or at least most) Co2 emissions were sequestered into concrete for roads or perhaps just buried under ground. There have been research projects, it seems like both would be possible and cost effective.

Please don't generalise like that. Not all environmentalists oppose every development, some of us only oppose the worst ones.

In my case I usually don't oppose anything, but sometimes I do want changes made before a development plan goes ahead. For example I would be perfectly fine with coal power plants if all (or at least most) Co2 emissions were sequestered into concrete for roads or perhaps just buried under ground. There have been research projects, it seems like both would be possible and cost effective.

Thank you.

Evidence? Infrastructure projects that have been endorsed by the major environmental lobbies, please?

Please don't generalise like that. Not all environmentalists oppose every development, some of us only oppose the worst ones.

In my case I usually don't oppose anything, but sometimes I do want changes made before a development plan goes ahead. For example I would be perfectly fine with coal power plants if all (or at least most) Co2 emissions were sequestered into concrete for roads or perhaps just buried under ground. There have been research projects, it seems like both would be possible and cost effective.

Thank you.

Evidence? Infrastructure projects that have been endorsed by the major environmental lobbies, please?

The pilot works great, according to the real world results wind (at least in this part of the country) is cheaper than nuclear power plants, and (obviously) greener than coal (which is what we currently use for ~100% of our energy generation).

The follow up plan was to build a larger wind farm to power 150,000 houses, which is almost the entire population in this part of the country (not very densely populated here, only one small city).

But after multiple good locations were approved all of them were subsequently cancelled due to grass root FUD campaigns (by other environmentalists) to block the project. Apparently wind generators emit high frequency sounds that cause serious health problems for anybody living nearby. And no, there isn't any science to back that up.

So we continue to use coal, except for the few thousand people living off the pilot wind farm and also a nearby hydro plant where a smallish river goes down a ~600m high mountain range, which feeds a decent amount of power into the energy grid as well.